The field of the invention is plywood fabrication and the invention relates more particularly to a process for strengthening plywood.
Applicant""s above-referenced patent shows a process for placing grooves in the outer surface of a skateboard to provide a skateboard which has a better xe2x80x9cpop.xe2x80x9d It also facilitates better slides. The specification and drawings of this patent are incorporated by reference herein.
Various processes for treating fibrous materials are known. One such process is shown in U.S. Pat. No. 4,233,752 where wood and other fibrous materials are held within a hermetically sealed heat insulated chamber. Pressure is applied to the fibrous materials and a vacuum is drawn on the interior of the hermetically sealed chamber to remove steam generated in the center of the fibrous materials. Numerous patents teach the shaping and placing of a curve in a stack of plywood panels. One such patent is U.S. Pat. No. 2,499,959.
It is an object of the present invention to process conventional plywood in a manner which increases its strength.
The present invention is for a process for increasing a load support weight before breakage of a piece of plywood. A plurality of plies are placed between an upper platen and a lower platen and the plies have an adhesive in between each of the plies. The upper ply and the lower ply are contacted with a hard face member having a plurality of spaced parallel pointed ridges parallel to the grain in the outer plies of the piece of plywood. The plurality of plies are subjected to sufficient pressure to cause the adhesive to bond the adjacent plies and to impress permanent parallel grooves in the outer surfaces of the piece of plywood thereby increasing their load support strength.